The disclosure relates generally to spectroscopy, and more specifically to systems and methods for measuring concentration of a trace gas in a gas mixture.
In a pipeline industry, an enormous amount of natural gas is transferred on a daily basis for applications such as power generation. This natural gas may include critical trace gas contaminants that may be hazardous in some circumstances. Also, these trace gas contaminants may cause damage to machinery, increase production costs, and/or degrade product quality and product value in industrial, chemical, medical, pharmacological, and energy applications. Thus, it is very important to detect and measure concentration of trace gas contaminants in the natural gas.
Typically, one or more trace gases in a gas stream may have interfering absorption from background gas, which in turn limits detection sensitivity or even may prevent detection of trace gas contaminants. In one of the conventional techniques, a differential spectroscopy may be employed to reduce spectral interference of one or more trace gases from the background gas. In the differential spectroscopy, a spectrum of the background gas is initially recorded. Further, this recorded spectrum of the background gas is subtracted from a spectrum of the natural gas to obtain a differential spectrum, which in turn is used to measure the concentration of a particular trace gas in the natural gas. However, this process requires a gas purifier and other requisite accessories to remove the trace gas from the natural gas to record the background spectrum, which may be costly. Additionally, this process requires a switch between the sample/natural gas to be analyzed and the reference/background gas, which may slow the system response time. Moreover, there is no guarantee that the spectral interference would be effectively removed because the spectra of the sample gas and the background gas are not recorded at the same time and may vary over time.
Accordingly, an approach that adequately addresses present issues regarding detecting trace gas and determining concentration of trace gas in natural gas is desirable.